HREM of the {111} surfaces of iron oxide nanoparticles

G. R. Lovely, A. P. Brown, R. Brydson, A. I. Kirkland, R. R. Meyer, L. Y. Chang, D. A. Jefferson, M. Falke, A. Bleloch

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Mixed phase Fe3O4-γ-Fe2O3 (magnetite-maghemite) iron oxide nanoparticles have been fabricated by colloidal routes. HRTEM/HRSTEM images of the nanoparticles show the presence of {111} facets that terminate with enhanced contrast, which is shown to be caused by the presence of additional cations at the edges of the nanoparticles. HRTEM images were taken on a FEI CM200 FEGTEM, a JEOL 3100 with a LaB6 source, and a double aberration corrected JEOL-JEM 2200FS FEGTEM. The enhanced contrast effect was observed on the {111} surface atomic layers resolved using each machine. HRSTEM images, taken on an aberration corrected STEM, resolved enhanced contrast at specific surface sites. Exit wave reconstruction was also carried out on focal series taken on a double aberration corrected JEOL-JEM 2200FS and showed similar highly resolved enhanced contrast at specific surface cation sites. It is apparent that additional cations are occupying the {111} terminating layers of these nanoparticle surfaces. The use of different microscopes and techniques in this paper provides strong evidence that the enhanced contrast is a real effect and not an effect caused by microscope aberrations.

Original languageEnglish (US)
Pages (from-to)389-395
Number of pages7
JournalMicron
Volume37
Issue number5
DOIs
StatePublished - Jul 1 2006
Externally publishedYes

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Keywords

  • Crystal surface
  • Exit wave reconstruction
  • HRSTEM
  • HRTEM
  • Iron oxide nanoparticles

ASJC Scopus subject areas

  • Structural Biology
  • Materials Science(all)
  • Physics and Astronomy(all)
  • Cell Biology

Cite this

Lovely, G. R., Brown, A. P., Brydson, R., Kirkland, A. I., Meyer, R. R., Chang, L. Y., Jefferson, D. A., Falke, M., & Bleloch, A. (2006). HREM of the {111} surfaces of iron oxide nanoparticles. Micron, 37(5), 389-395. https://doi.org/10.1016/j.micron.2006.01.005